Here’s
what the biologists did: They collected monarchs, divided them into
three groups, and put them under artificial light conditions in their
lab.

The
control group received light during normal daylight hours, but the two
test groups were “clock-shifted.” They were exposed to 12
hours of light but not during normal daylight hours.

Control Group:The control group received light during
normal daylight hours They received light from 7 am to 7 pm.

"Early"
Group: This group was “clock-shifted” 6 hours early.
They received light from 1 am to 1 pm. (This means that when it was
actually 1 am, the daylight conditions were made to look like 7 am.
When it was 1 pm the light looked like 7 pm and so on.)

"Late"
Group: The other group was “clock-shifted” 6 hours
late. They received light from 1 pm to 1 am.
(This means that when it was actually 1 pm, the daylight conditions
were made to look like 7 am. When it was 1 am the light looked like
7 pm and so on.)

After
5 days, the butterflies were taken outside. Their flight direction was
tested under normal daylight conditions. Which way do you think each
group flew?

Predict:
What
do you think happened to the monarchs? Explain
your thinking.